The use of a ramp to facilitate the transfer of loads to and from the bed of a pickup truck or a like vehicle is well known. A principal problem that arises in connection with the use of these ramps is that of suitably storing such ramp while it is not in use. If the ramp is to be transported along with the load, it must occupy valuable load carrying space, either along the sides of the truck bed, see for example U.S. Pat. No. 3,737,058 granted to Johnson on June 15, 1973; or along the floor of the truck bed, see for example U.S. Pat. No. 3,613,920 granted to Flamm on Oct. 19, 1971. An additional problem has been that the ramps are totally useless while being transported.
There have been a number of attempts to provide for the use of loading ramps and yet minimize the loss of carrying space in the truck while the ramps are being transported. U.S. Pat. No. 3,642,156 granted to Stenson on Feb. 15, 1972, features a series of ramp sections which fold into one another in accordion-like fashion. The size of the ramp is limited in this arrangement, however; first by the fact that each succeeding section must be narrower than its predecessor, and secondly by the height of the tailgate itself. This problem is especially apparent where the load is heavy and a particularly long ramp is required to provide sufficient mechanical advantage. A similar limitation upon the size of the loading ramp is seen in U.S. Pat. No. 3,756,440 to Raap et al., granted on Sept. 4, 1973, where the length of the ramp would be strictly limited to the width of the pickup truck tailgate. Another ramp involving hinged sections is shown in U.S. Pat. No. 3,713,553 to Curtis et al., granted on Jan. 30, 1973. The Curtis invention significantly reduces the space used by the ramp in storage, but like the preceding two devices, it is also limited by the size of the tailgate. A further problem common to all ramps mounted on a tailgate is that the tailgate, rather than the truck bed, bears the weight of a load upon the ramp. This prevents the use of such a ramp for the loading of extremely heavy objects.
All of the above cited prior art devices occupy at least a portion of the usable carrying space of the truck in which they are being transported. In addition, they serve no useful purpose while in transport.
In transporting cargo loaded up a ramp and/or other cargo in an open pickup truck it is often highly desirable and sometimes necessary to provide at least temporary side walls on the truck.